Package with easy opening device



Feb. 24, 1970 A. c. TRACY 3,497,131

PACKAGE WITH EASY OPENING DEVICE Filed May 20, 1968 INVENTOR ALAN C.TRAC Y United States Patent PACKAGE WITH EASY OPENING DEVICE Alan C.Tracy, Davenport, Iowa, assignor to The Kartridg Pak Co., Davenport,Iowa, a corporation of Iowa Filed May 20, 1968, Ser. No. 730,411 Int.Cl. B65d 65/28 US. 'Cl. 22966 5 Claims ABSTRACT OF THE DISCLOSURE Apackage and a method of forming the same wherein a plastic film isformed into a tube and filled with a flowable product, margins of thefilm being overlapped and sealed with a tear strip in the seam thusformed which is fabricated of a material having a tear strength greaterthan the film, which has a width sufficient to extend along both sidesof the seal line and a length sui'licient to extend the full length ofthe package so that the ends thereof are anchored in the ends of thepackage which are gathered and sealed with bendable clips of metal orsimilar material. A pair of longitudinally spaced transverse slits arecut in the outside edge of the tear strip and the film margin tofacilitate tearing either circumferentially or longitudinally so as toopen the package.

This invention relates to packaging and is more particularly concernedwith improvements in a package which is formed of plastic film and whichhas a tear strip means for facilitating opening of the package.

Various types of packages have been developed for use in the marketingof foodstuffs or similar products which are in a flowable state. Onepackage which is designed particularly for this purpose is formed byfeeding the product into a tube of relatively thin, pliable plastic filmmaterial and closing the ends of the tube by gathering and sealing theend portions of the tube with bendable metal clips, One such packagewhich has been employed successfully for some time in the packaging offoodstuff, particularly, comminuted meat products, spreads, cheese andthe like, is described in Patent No. 2,831,302, granted to H, A. Jensenand A. H. Eberman, on Apr. 22, 1958. In this package a film is employedwhich generally has a relatively high resistance to tearing orpuncturing so as to withstand, without injury, the relatively roughhandling encountered in the marketing of the package. The package has alongitudinal or axially extending seal formed in overlapping margins ofthe film material which has been eifected by the use of electronicequipment resulting in the welding of the plastic film along arelatively narrow line. When this package is formed from a film having alow moisture transmitting characteristic, for example, Saran, which hasbeen used extensively for packaging meat products, the resultant packagehas a relatively long shelf life and the product is not subject to rapiddeterioration. However, because of the resistance of the package film totearing, it is generally necessary for the consumer to cut or puncturethe film with a knife or other sharp instrument in order to open thepackage. Various schemes have been proposed for providing this type ofpackage with tear strip or tear cord arrangements so as to facilitateopening of the same but none of the arrangements proposed have provensuccessful. For various reasons they have not been acceptable to themanufacturers of this package or to the consumers who use it. It haslong been recognized that a satisfactory device for facilitating theopening of this package which would not require the use of any kind of atool would make the package more acceptable to the user and would bequickly adopted by the manufacturers provided it did not increase thecost unduly. A general object,

therefore, of the present invention is to provide a package of thischaracter having an improved easy opening feature which may beincorporated in the package without detracting from its appearance andwithout an appreciable increase in the cost of producing the same.

It is a more specific object of the invention to provide in a packagefor a flowable product which is formed by overlapping and sealing themargins of a film to provide a tube, filling the tube with a flowableproduct and gathering and closing the same at opposite ends byapplication of a bendable clip, an easy opening device which isincorporated in the longitudinal seam and which is so constructed thatit facilitates opening the package by tearing the packaging film eitherlongitudinally along the seam or transversely about the periphery of thetube.

A further object of the invention is to provide in a tubular packagehaving a longitudinal seam formed in overlapping margins of thepackaging film and with the ends gathered and closed by bendable clips,an easy opening device which is in the form of a tear strip interposedbetween the film margins forming the longitudinal seam and extending thefull length of the package with its ends anchored by the end closureclips.

Another object of the invention is to provide a tubular package having arelatively narrow, longitudinally extending seal formed in overlappingmargins of the packaging film and end seals formed by gathering thetubular material and applying a bendable metal clip, wherein a tearstrip which is formed of a material having a tear strength greater thanthe packaging film is interposed between the overlapped film margins andsealed to the oppositely disposed faces thereof with the tear stripextending the length of the package so that the ends are anchored by theend closure clips and with a side marginal portion extending outside ofthe seal forming area and accessible so that it may be gripped and tornto break the seal and open the package.

Still another object of the invention is to provide in a tubular packagehaving a longitudinal seal formed by overlapping marginal portions ofthe packaging film, a longitudinally extending tear strip interposedbetween the seal forming margins with the side edge extending to theexterior of the package where it is accessible so as to be gripped andpulled to tear the package open, and spaced transverse slits in theexposed side edge of the tear strip for facilitating the tearing of thepackaging material either transversely of the seam or longitudinallythereof.

These and other objects and advantages of the inven* tion will beapparent from a consideration of the package and the method of formingthe same which is shown by Way of illustration in the accompanyingdrawings wherein:

FIGURE 1 is a perspective view illustrating a package of tubular formwhich has incorporated therein the principal features of the invention;

FIGURE 2 is a cross sectional perspective to an enlarged scale, taken onthe line 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary cross section through the seal area, to astill larger scale, the view showing the laminated tear strip elementemployed in the package of FIGURE 1;

FIGURE 4 is a perspective view, largely schematic, illustrating themethod of forming the package of FIGURE 1.

Referring to FIGURES 1 and 2 of the drawings, there is illustrated apackage 10 which has incorporated therein an easy opening deviceembodying the principles of the invention.

The package 10 is in the form of a tube and is adapted to be fabricatedfrom a single length of plastic film 11. The particular type of filmemployed will depend upon the nature of the product which is to bepackaged. When the product is processed meat, such, as, a sandwichspread or the like, the preferred packaging material is Saran which ishighly resistant to the transfer of moisture and serves to retain theflavor in the product and resist deterioration so as to provide arelatively long shelf life. Other film materials may be employed such asPliofilm, polyethylene and the like, depending upon the nature of theproduct and the characteristics desired in the film.

In forming the package the tubular shape is accomplished by overlappingand sealing the side marginal portions 12 and 14 of the film 11. In thepackage 10 illustrated in FIGURES 1 and 2, a relatively narrow tearstrip 15 is interposed between the overlapped margins 12 and 14 of thefilm 11 and an RF or electronic type seal 16 joins the tear strip 15 tothe overlying and underlying film margins 12 and 14 throughout thelength of the package. The package 10 is closed at its opposite ends bygathering the tube material and applying bendable clips 17 and 17' whichmay be formed, for example, of a suitable metal such as aluminum. Thetear strip 15 extends the entire length of the package 10 so that itsends are anchored in the end seals formed by the clips 17 and 17'.

Preferably, the tear strip 15 is formed as a laminate (FIGURE 3) with aninterior ply 18 and exterior plies 20 and 20'. When the packagingmaterial is Saran the exterior plies 20 and 20' are preferably the samematerial so as to readily seal with the packaging film when theelectronic sealing occurs as shown in FIGURE 3. The inner ply 18 ischosen for its tensile strength and resistance to the sealing action. Apolyester film may be employed with the Saran which is not affected byelectronic sealing but which may be surface bonded by heat or by othersealing methods to the Saran so as to form a laminate. Othercombinations of materials may be employed with an adhesive bond betweenthe plies of the tear strip which will prevent delamination and with thecenter ply unaffected by the seam sealing action so as to permit tearingacross the seal. The tear strip may be opaque, translucent or aconstrasting color, as desired.

To locate the point for the beginning of the tearing where desired andto facilitate the start of the tearing action, particularly, where thefilm material has substantial resistance to tearing, a pair of slits 21and 22 are cut in the exposed margin of the tear strip 15 and adjacentportions of the outer film margin 12. The slits 21 and 22 extend in adirection transversely of the longitudinal axis of the tube and are ofsufficient length to extend into the margin of the packaging film butterminating short of the seal 16, as shown in FIGURES 1 and 2. Thematerial between the slits 21 and 22, indicated at 23, may be graspedand pulled in the direction of the seam or seal 16 to tear around thecircumference of the package for opening the same. If desired, thematerial may be grasped adjacent the slit 21 in FIGURE 1 and pulled inthe longitudinal direction across the longitudinal seam 16 to tear alongthe latter for opening the package.

As illustrated in FIGURE 4, the present package may be most convenientlymade by feeding a continuous web W of a film material which is suitablefor forming the package over the end of a hollow mandrel M through whichthe product is fed, folding the web to overlap side margins of the sameand simultaneously feeding a continuous web T of the tear strip materialbetween the overlapped film margins with the one side edge extendingbeyond the outside lap of the film material, sealing the multi-plymaterial formed by the overlapped film margins and the tear strip bymeans of an electronic sealing mechanism, indicated at S, so as toprovide a continuous longitudinal seam, applying pairs of transverseslits 21 and 22 at the proper intervals by means of a slitting knife andco-operating anvil assembly, indicated at C, constricting the filledtube at intervals after it advances beyond the discharge end of themandrel M, applying pairs of the closure clips 17, 17' to theconstricted sections of the tube and cutting between the clips 17 and17' of each pair thereof. These operations may be carried outmechanically by proper modification of the package forming machinedisclosed in Patent No. 2,831,302 so as to feed the tear strip and placethe slits 21 and 22 in the proper location.

While particular materials and specific structural details have beenreferred to in describing the package illustrated and the method andapparatus for forming the same, it will be understood that othersuitable materials and equivalent structural details may be resorted towithin the spirit of the invention.

I claim:

1. In a package comprising an elongate, generally tubular container ofrelatively thin plastic film material which has longitudinally extendingside margins overlapped and sealed by a longitudinal seam and the endsthereof being gathered and tightly closed by clips of bendable material,a tear strip interposed between said overlapped side margins and sealedthereto, said tear strip having a tensile strength greater than saidfilm, said tear strip extending substantially the full length of thelongitudinal seam and having a side edge portion projecting beyond theseam which edge portion is free so that it may be grasped and pulledback across the seam area to tear open the package.

2. In a package as set forth in claim 1, and said tear strip beingformed of laminations which are surface bonded to each other and outsidelaminations of said tear strip being sealed to said overlapped marginsof the container film material forming the longitudinal seam.

3. In a package as set forth in claim 1, and said tear strip having aplurality of plies of material with outermost plies being a materialwhich is readily sealable with the overlapped film margins in the seamarea, and being joined thereto in said seam area, and with an inner plyof a material which is not affected by the seam sealing action and whichwill result in tearing of the film material when the projecting edge ofthe tear strip is grasped and pulled back across the seam area.

4. In a package as set forth in claim 1, and a pair of spaced transverseslits cut in the projecting side edge portion of said tear strip andextending into the outermost margin of the overlapped film materialwhich facilitates the tearing of the material and enables the package tobe readily opened by grasping the tear strip and tearing around itsperiphery or along the longitudinal seam.

5. In a package as set forth in claim 2 and said tear strip having itsside edge margins extending on both sides of the seam forming seal areaand the outermost side edge portion of said tear strip extending beyondthe margin of the film material which is outermost with said extendingportion being free to facilitate grasping to tear open the package.

References Cited UNITED STATES PATENTS 2,121,564 6/1938 Herron.

2,811,455 10/1957 Erekson 229--55' X 3,362,615 l/1968 Rodda 229513,391,617 7/1968 Wise et a1 9336.2

DAVID M. BOCKENEK, Primary Examiner U.S. Cl. X.R. 206--46; 22951

